> For the complete documentation index, see [llms.txt](https://naviprotocol.gitbook.io/navi-protocol-developer-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://naviprotocol.gitbook.io/navi-protocol-developer-docs/smart-contract-overview.md).

# Smart Contract Overview

This guide outlines key modules that support essential functions such as lending, borrowing, repaying, rewards distribution, and flashloan. Each module is broken down with detailed descriptions of its use cases and key functions, providing developers a clear understanding of how NAVI’s system operates.

The functions within this module are categorized into two types: **entry** and **non-entry functions**.

* **Entry Functions**:
  * Directly invoke the underlying base function.
  * Automatically return the token object to the function sender.
* **Non-Entry Functions**:
  * Also invoke the underlying base function.
  * Return the coin object without handling it.
  * Require the caller—typically a developer or transaction builder—to manage the token object manually. Failure to do so will result in a reverted transaction.

Non-entry functions provide greater flexibility, enabling developers to improve interoperability and compatibility with other protocols.

## Modules covered include:

{% content-ref url="/pages/vGNkCIXYYd53VSiehBui" %}
[Lending Core](/navi-protocol-developer-docs/smart-contract-overview/lending-core.md)
{% endcontent-ref %}

{% content-ref url="/pages/qB6nNnfnRSJSiG4pYLex" %}
[Flash Loan](/navi-protocol-developer-docs/smart-contract-overview/flash-loan.md)
{% endcontent-ref %}

{% content-ref url="/pages/wfcZ58YaF2v8S8nMUlgZ" %}
[Calculator](/navi-protocol-developer-docs/smart-contract-overview/calculator.md)
{% endcontent-ref %}

{% content-ref url="/pages/gUUa0Bd53JuNTrm4KQB3" %}
[Dynamic Calculator](/navi-protocol-developer-docs/smart-contract-overview/dynamic-calculator.md)
{% endcontent-ref %}

{% content-ref url="/pages/Fxzr4kqsYu6avApSJPlG" %}
[Storage](/navi-protocol-developer-docs/smart-contract-overview/storage.md)
{% endcontent-ref %}

{% content-ref url="/pages/nulOh5niMKAoXgszb2Fp" %}
[Release History](/navi-protocol-developer-docs/smart-contract-overview/release-history.md)
{% endcontent-ref %}

## Github Repo of NAVI Interfaces:

{% embed url="<https://github.com/naviprotocol/protocol-interface>" %}
NAVI Interface Repo
{% endembed %}
